To understand the working principle of torque converter, let us take two fans for illustration, one fan is connected to the power source and the other fan is not connected. When first fan connected to the power source starts moving, the air from it flows to the second fan whose blades are stationery. The air from the first fan strikes on the blades of the second fan and it also starts rotating almost at the same speed of the first fan. When the second fan stopped, it does not stop the first fan and it keeps rotating. On the same principle the torque converter works.
The impeller or pump acts as first fan connected to the engine and turbine act as the second fan connected to the transmission system. When the engine runs, it rotates the impeller and due to the centrifugal force, the oil inside the torque converter assembly is directed into the towards the turbine. As the oil hits the turbine blades, it starts rotating. This makes the transmission system rotates and the wheels of the vehicle moves. When engine stops, the turbine also stops rotating but the impeller connected to the engine keeps moving and prevents the engine from being stalled.
The impeller or pump acts as first fan connected to the engine and turbine act as the second fan connected to the transmission system. When the engine runs, it rotates the impeller and due to the centrifugal force, the oil inside the torque converter assembly is directed into the towards the turbine. As the oil hits the turbine blades, it starts rotating. This makes the transmission system rotates and the wheels of the vehicle moves. When engine stops, the turbine also stops rotating but the impeller connected to the engine keeps moving and prevents the engine from being stalled.